Quote:
Originally Posted by Tony 289  Pete
Fab thanks for all the info. really helpful. The inlet manifold is the original I modified to take Holley etc. Its 360 and works well on the 3.5. Was thinking of getting the compression up with piston and conrod combo from JE and using the old tin type gasket. I am from the Hornchurch, Essex area. Stick on 18 always. |
Hi Tony,
When you say getting the compression up with a piston kit was that for the 3.5 or the 4.6 that you are building?
Hasn't your 4.6 short engine got any pistons?
I could be wrong but I don't think that you can get tin gaskets for the 4.6. Even if you could I would not use them! When you take your 3.5 heads off if its using them you'll see what I mean! (Especially if you've used the dodgy outer bolts. The gaskets will have started to go brown near the valley area, this is the start of gasket failure).
You will certainly need to get the CR up if you want the most out of the 4.6 as the 3.5 heads have larger chambers. My 4.6 lump had the high compression 9.35:1 pistons fitted but it would have not even been that lowish figure with the larger heads! (I've got the figures at home, I think it was either high 8.??:1 or maybe 9.00:1....both pretty crap!)
Like I said in my first post the problem with skimming 70 odd thou off is that it messes a few other things up that can only be sorted by more machining!
The top end BHP that you'll get from going to the 4.6 is great but the bottom end torque is even more fun, my car will pull top gear from about 1300-1500 rpm! (The 3.5 would have stalled if I tried that!)
Essex is a bit far from me, luckily for you otherwise I'd come over with my burette to annoy you!
Not sure what you mean by "stick on 18 always" ??
If you need anymore advice just post or PM me.
By the way you must read Des Hammills V8 tuning book before you build you engine, all the info I used came from that book, it is required reading material!
You should also read it so that you know about the cracked block dropped liner issues that these blocks can suffer...not nice to read but it's better to know.
When you strip your 3.5 you need to look at the valve train components VERY carefully, you maybe disappointed to find that some of the bits are worn out, stuff like rockers and rocker shafts. Your 3.5 may have been running fine but the stuff can still be worn out, it would be daft to use them if they're not in very good condition.
Pete